Safety in Formula One.

Motor racing is, by its very nature, dangerous. That's the reason some people do it; and why a lot of people don't. In the past ten years, however, safety standards have improved so much in Formula 1 that the growing expectation is for drivers to walk away from their accidents, no matter how severe.

No accident illustrates the incredible safety of a modern Formula 1 car better than Jenson Button's spectacular 170mph, 20G crash during practice for the 2003 Monaco Grand Prix. "I was on a really good lap," said Jenson the next day. A bit too good, as it turned out.

Exiting the famous tunnel and braking for the Harbour Chicane, Button's Lucky Strike BAR Honda 005 clipped the outside guard rail, which catapulted him into the inside Armco, before sliding out of control down the hill and slamming into another barrier side-on. Jenson was unconscious when the track marshals arrived at his car, but he soon came round. After spending the night under surveillance at the Princess Grace Hospital, he was up and about in the paddock before the race the next day. "I feel fine," he said, "although my head's still a bit groggy, but that'll clear up pretty quickly."

Jenson wasn't fit to race - and of course hadn't set a qualifying lap - but even so; just a groggy head after that kind of impact is nothing short of miraculous, and a great testament of modern F1 safety. But how did we get here? How did the fastest category of formula racing also become the safest? And what is it about a modern F1 chassis that makes it so safe?

A brief history lesson.

The gradual improvement in F1 safety quickened dramatically as a direct result of the terrible deaths of Ayrton Senna and Roland Ratzenburger at the San Marino Grand Prix at Imola in 1994. There hadn't been a death in F1 until that point for eight years (since Elio di Angelis died in testing at the Paul Ricard circuit in France in 1986). The FIA, the sport's governing body, had employed relatively successful measures to slow cornering speeds after di Angelis's death, but there was a lingering reluctance among the teams to introduce more stringent technical regulations to cover the wider issues of driver safety. Under the terms of the Concorde Agreement, changes to technical regulations cannot be made without the unanimous agreement of the teams, so the situation reached a stalemate, despite the quietly voiced concerns of many within the sport.

In the aftermath of the Imola tragedies, however, FIA president Max Mosley overruled the unanimity requirement and took serious action. Mosley formed an Advisory Expert Group (AEG) on safety, under the guidance of Professor Sid Watkins, along with experienced F1 engineer Harvey Postlethwaite and F1 driver Gerhard Berger. It was the beginning of a whole new era of F1 safety.

The AEG took a rigorous, scientific approach to the issue, using modern data-analysis and impact testing techniques to scrutinise every aspect of car safety, coming up with a set of regulations to optimise the protection offered to the driver. The sport's approach had never before been so scientific. Previous measures taken had been sensible, logical and effective, but the sport needed to take advantage of modern methods in order to keep up with modern standards.

The technical regulations now stipulate a set of required dimensions for the driver's 'survival cell', around which the whole of the rest of the car must be designed. In many ways, a modern F1 chassis is a survival cell with bits added on. The basic dimensions of this survival cell were determined by the AEG to provide optimum protection to the driver in the four main types of impacts: front on, front-angled, side and rear.

One of the most important steps taken was to significantly raise the sides of the cockpit to protect the driver's head. Another key development was the introduction of Confor foam in a standardised driver headrest in 1995. Confor decelerates the driver's head in a much more controlled way compared with other materials. To supplement the protection for side and rearwards impact, the seat belts and HANS device restrain the driver and head in a full frontal impact. Also introduced by the AEG was a geometric regulation that prevents disconnected wheels from hitting the driver. A heavily revised set of crash test procedures also led to a more general increase in chassis toughness, which today is one of the most impressive things about an F1 monocoque.

The here and now...

So what precisely is it about an F1 monocoque that makes a big accident such as Button's a relatively safe proposal today compared with ten years ago?

There are three main principles that need to be followed when it comes to driver protection in an accident:

1. The driver must be held in a position where his body can be supported to take the massive loads associated with rapid deceleration: seat straps, contoured seat, head rest and the HANS (Head And Neck Safety) device all serve this purpose.

2. The driver must be protected from being hit by debris and sharp objects: high cockpit sides and penetration resistance of the carbon composite tub itself.

3. The car must have enough room to decelerate: a driver is more likely to survive an impact if the energy from the impact is dissipated over a longer period of time.

"Giving the car time to slow down is perhaps the biggest problem we have now," explains BAR's technical director Geoff Willis. "The cars are tougher than the drivers. We can build a car to withstand almost anything, but the driver won't necessarily survive it."

The structures between the bodywork and the monocoque are designed to do this to an extent: in the side of the BAR 006, for example, there are carbon composite crush tubes, and further back other internals such as radiator ducts and exhaust ancillaries which absorb some of the energy. "But you still want a tyre barrier or an Armco at circuits - something with a bit of give in it to slow the car down more gradually," says Willis.

Fortunately for Jenson, the barrier with which he became well acquainted at Monaco was heavily armoured with tyres. What may seem a primitive safety method is actually a very effective way of reducing the loads exerted on a driver. In Jenson's crash, although the loads were quite high, the tyre barrier certainly helped reduced them to a level which he could withstand, and a level way below the car's threshold. "We just took off the radiator ducts, the body work, the side impact tubes, cleaned off the bits - and the same car was racing again two weeks later in Canada," says Willis proudly.

Indeed, although Jenson's crash was a high speed spectacular, the loads going through the chassis didn't even approach the magnitude that would be required for any kind of structural failure in the carbon composite survival cell. This is because all monocoques must pass a set of crash tests that go way beyond the expected loads in even the worst accident.

Crash tests.

The FIA's crash tests have recently been criticised by some for being too stylised, failing to accurately simulate a real life F1 crash. The concern is that the process of passing the tests has become somewhat arbitrary: cars are being designed specifically to pass the tests, which doesn't necessarily lead to their being safe.

However, Willis couldn't disagree more: "The side impact test is quite stylised, in that it is at exactly 90degrees in a certain position at a certain height. But as a knock on of having to pass the test, we have a very strong structure on the side of the chassis. The test does not in itself make the car safe, but in order to pass it, you have to make a car that is intrinsically safe."

The side impact test is complemented by the side penetration test, which ensures the driver is protected in the event of being 'T-boned' by another car. Again, the test is quite stylised but it means the survival cell must demonstrate incredible resistance to penetration. A 550mm by 550mm panel of the same carbon fibre laminate used on the side of the chassis must be able to withstand a load of 150KN from a simulated nose being pushed into it. That equates to the laminate withstanding around 15tonnes exerted through something six inches in diameter.

The same piece of laminate must also be able to absorb 6KJ of energy in the penetration test, to ensure that the survival cell is flexible enough to be sufficiently energy absorbing. This requirement entails a significant design compromise, since designers strive to make chassis as stiff as possible to gain performance on track. The test means the side of the monocoque must have a certain spring to it, which limits the modulus (stiffness) of the carbon fibre laminate used on that part of the car.

"There are very high modulus carbon fibres, but they don't absorb much energy, so you wouldn't really want to have them there in an impact," explains Willis. "They would give you more stiffness for a given weight, but by having this combination of strength and energy absorption in the test, we end up with a chassis laminate with a certain amount of toughness."

There are three other major tests: front impact, rear impact and roll hoop. The front impact test is relatively straight forward: teams have understood how to make strong nose cones for many years. The roll hoop is significantly trickier: the current test requires it to withstand around 12 tonnes, the roll hoop itself weighing only a few kilos.

It is the rear impact test, however, that provides the greatest challenge for the teams, the current design trend for wasted rear-ends providing an aerodynamic advantage which must always be compromised owing to the requirements of the test. The rear impact test was this year particularly challenging for BAR, the 006 featuring a carbon composite gear box casing, which had to be carefully designed to take the test loads.

The future?

An F1 monocoque is now one of the safest places you can be. Nevertheless, FIA president Max Mosley has recently intimated his concern at ever increasing cornering speeds and ever tumbling lap times. It is likely that the future will bring smaller engines (2.4 litre V8s instead of 3.0 litre V10s, suggested for 2008 if not before) and a change in tyre regulations. The tyre war between Michelin and Bridgestone has in recent years pushed F1 performance more than any other factor.

Something will have to be done at some point to maintain current levels of safety, but exactly what and when is still unclear. Either cars are slowed down or circuit run-off areas become even bigger. However, in an age when F1 is trying not to push fans any further away, it is unlikely to be the latter.